Fractal models for luminescence probing of organized assemblies. Studies with respect to the nature of the assembly, the temperature, and the quencher concentration

Abstract

Small unilamellar phospholipid vesicles, SDS and SDS-pentanol micelles, and water-in-oil quaternary microemulsions have been studied with pyrene and Ru(bpy) ²⁺₃ . The decay profiles have been fitted with the equation I(t)=I ₀exp(−k ₀ t) exp(−k′Q ^{t f} + k″Q ^{t 2f}) (Chem. Phys. Letters (1990) 165:35-40). In SDS micelles this equation applies only in the presence of pentanol and at high temperature, so that the exchange rate between micelles becomes 2.3 × 10⁹ M⁻¹ s^t-1. In electrically percolating w/o microemulsions k″ becomes zero. Increase of temperature always increases the reaction rates, while f is substantially affected only in the case of lipid vesicles. Change of quencher concentration affects both f and the reaction rates in some cases.